LES-CMC simulations of a lifted methane flame

Numerical simulations are performed for a lifted diffusion flame produced by a partially premixed jet issuing into a vitiated co-flow. This configuration poses particular challenges to the combustion model due to a very sensitive balance between chemical reaction and species diffusion that determines the liftoff height above the burner exit. In the present study the flow field is solved using Large-Eddy-Simulation and the combustion model is based on the Conditional Moment Closure (CMC) approach. A detailed mechanism of 44 species and 256 reactions is used to represent the chemistry. LES-CMC is able to predict flow characteristics and reactive species concentrations well, the variation in lift-off height due to inflow turbulence can be captured with some success, and ignition trends are reproduced satisfactorily. (C) 2009 The Combustion Institute. Published by Elsevier Inc. All rights reserved.